Hydraulic door-keeper



Dec.27,1960 H. BO'MM 2,965,917

HYDRAULIC DOOR-KEEPER I I 2 eats-Sheet -1 Filed Dec. 4. 1956 Dec. 27, 1960 HYDRAULIC DOOR-KEEPER Filed Dec. 4, 1956 2 Sheets-Sheet 2 Hg. 4

402 'Il'lll r-l. BOMM 2,965,917 I United States Patent HYDRAULIC DOOR-KEEPER Heinz Bomm, Ennepetal-Voerde, Germany, assignor to Frrma Diirken & Mankel KG., Ennepetal-Voerde, Germany Filed Dec. 4, 1956, Ser. No. 626,235 Claims priority, application Germany Aug. 3, 1956 4 Claims. (CI. 16-55) The invention relates to a hydraulic door-keeper having a pivot and a torsion spring arranged with its axis parallel to the said pivot, as well as linkages connecting the spring to the pivot for a door swing of at least 180.

Hydraulic keepers of a great many difierent types are known, both for doors opening in one direction and for swinging doors. Swinging-door keepers have a swing of 180, while keepers for doors opening in one direction generally have a swing of only 90. However, keepers having a swing of 180 for doors opening in one direction are also known. Difiiculties commonly arise in connection with accommodating the keeper within a small space Without sacrifice of efiiciency of the mechanism. Thus all known door-keepers have disadvantages consisting either in large size, requiring a large floor opening, or in unsatisfactory function, or both. Door-keepers which are to be set in the floor should be constructed as low as possible in order to keep the area of the floor flat. Furthermore, such door-keepers have to keep the door firmly in closed position even with a rolling lock with a falling latch and have to prevent the door from fluttering in the Wind.

This requires a high locking pressure of the spring. Since the opening of the door puts the spring under tension and thus increases the spring pressure, a decrease of the spring pressure acting on the door wing has to be aimed for, in order to facilitate the opening of the door wing over its entire swinging area.

It is the object of the invention to provide a unilateral and a swinging door-keeper which meets all the requirements and eliminate the disadvantages above noted.

In the case of the unilateral door-keeper it becomes possible for the first time to effect a replacement of the door over a swinging angle of 180 by means of a single spring, thus the power exerted on the door in order to open it, decreases a little at first and later remains almost the same until the full opening angle has been reached.

The device according to the invention will now be more fully described with reference to the accompanying drawings, but it should be understood that these are given by way of illustration and not of limitation and that many changes in the details may be made without departing from the spirit of the invention.

In the drawings:

Fig. 1 shows an embodiment of a keeper for swinging doors in longitudinal section along the line II in Fig. 2;

Fig. 2 is a top view of the same embodiment with the cover plate removed, partially broken away and omitting, for the sake of clarity. the lines drawn in Fig. 4a to represent the guide roller of the damping mechanism;

Fig. 3 shows a transverse section along the line Ill-III in Fig. 2;

Fig. 4 is a transverse section showing the lever system at the section line IV-IV in Fig. 1, with door closed;

Fig. 4a is a transverse section showing the connections to the damping mechanism at the section line IVa-IVa in Fig. 3, in the same position of the door as in Fig. 4;

2,965,917 Patented Dec. 27, 1960 Fig. 5 is a sectional view taken on the same section line as Fig. 4, showing of the lever system with the door opened counterclockwise;

Fig. 6 is a sectional view taken on the same section line as Fig. 4, showing of the lever system with the door opened clockwise;

Fig. 7 is a longitudinal section of the cushion chamber as seen from above, with door closed;

Fig. 8 is a longitudinal section of the cushion chamber with the door open.

In Figs. 1 to 8, a housing 1 accommodates all mechanical parts including the hydraulic damping system, and is closed off dustproof at the top by cover plates 2 and 3. The pivot 4 revolves in a bearing boss 5 in cover 2 and a thrust bearing 6 in the bottom of housing 1. In the center of bearing 6, as a foot bearing to carry the weight of the door, a large ball is accommodated, the upper half of which fits a matching recess in the pivot 4. Cover plate 3 has a bearing boss 7, and the bottom of housing 1 carries another bearing 8, for the winder 9 of spring 14. The bottom pin of the winder bears a lever 10. The lever 10 is fixedly attached to the winder by a screw 11, Figs. 4, 5, 6. The lever 10 is connected to the pivot 4 by connecting rods 12, 12' and cranks 13, 13. The connecting rods 12, 12 are articulated to the lever 10 with pins located both on the same side of the line between centers of the pivot and spring.

At the other end, connecting rods 12, 12' are articulated to the cranks 13, 13', arranged substantially symmetrical to the line between centers of the pivot and spring. The cranks lie one above the other, are rotatably mounted on the pivot 4, and include a catch 15, in one piece with the pivot, between them.

Catch 15, which has a projecting ear, indicated as 15', is positioned non-rotatably on pivot 4. The two cranks 13 and 13' each present an upwardly pointing projection, referred to in Fig. 4 by reference numerals 13 and 13'. Depending on the direction of rotation of pivot 4, one or the other of the projections, and with it the corresponding crank arm 13 or 13', are taken along.

The restoring spring 14, for example a spiral spring, is hooked by its outer flange 14 to housing 1 and by its inner flange 14" to the winder 9, and, when wound, will pull lever 10 and connecting rods 12, 12' steadily in the direction of arrow a (Fig. 4) until cranks 13, 13' rest against the catch 15. A rigid connection is thus formed, from spring 14 to the square 16 on pivot 4, transmitting the closing force of the spring to the door through a lever mounted on the square. In the position described and represented in Figs. 2 and 4, with door closed, the initial force of the spring acts to draw cranks 13, 13' hard against the faces of catch 15, thus holding the door in closed position. The articulations of connecting rods 12, 12, both on the spring side and on the pivot side where they join the cranks 13, 13', are so chosen that the highest closing pressure is provided in the first 1020 of opening to the right or left. This means conversely a maximum closing pressure in the last 10-20 of the closing motion, or precisely in the critical range of closure. This ensures positive closing of the door at the end of the closing operation and retention of the swinging door in middle position. If the door is opened in the direction of the arrow in Fig. 5, then catch 15 will press against the lug of crank 13, while connecting rod 12 will pull up the lever and wind the spring. The construction allows the door to open right and left up to Over the distance from 0 to 110, the torque on the door is constant within the first 20.

Depending on the strength of the spring installed, the torque on the door will then decrease by /s to A, this decrease ending at about 40. torque remains constant.

This is due not only to the length of the cranks 13 and 13' and lever 10, but also to the position of the swing of these relative to the line joining the pivot and the pin of the spring, as well as the variation of the spring force with angle of swing of the door. The leverage of the lever, on commencement of closure at 110", is very long, becoming less until the minimum lever arm is reached at the end of the closing operation. At commencement of closure, the spring 14 is much more strongly wound than in rest position, transmitting its force via the engaged crank 13 to the catch 15, which tends to turn the pivot 4 and hence toclose the door. The connecting rod 12' with crank 13 meanwhile executes an idle movement on the other side of pivot 4, without transmitting any force or action. If the door is moved clockwise, or in other words in the direction of the arrow in Fig. 6, the process is the same except that now connecting rod 12 with crank 13' transmits the force and movement, while connecting rod 12 and crank 13 follow idly.

After removal of cover plate 3, the spring 14 can be removed and replaced by another if necessary. To permit adjustment of initial tension, the top pin of winder 9 has an internal hexagon 29 to receive a wrench. By means of the wrench, the winder 9 is moved in the direction of winding the spring 14 until, through a clo'able opening provided in the cover plate 3 and one of the holes arranged around the entire circumference of the winder 9, the screw 11, Fig. 4, becomes visible. Screw 11 may be screwed into a threaded hole of lever 10. Under screw 11, in the locking position of the swinging door, as seen in Figs. 2 and 4, there is provided a cavity (in the axial prolongation of said screw 11), into which the screw can be screwed down; this screw fiIlt arrests the rotation of member about the axis of the spring. As the screw 11 is screwed down further, the upper part of screw 11 finally leaves the bore in the spring core 9, so that this can be turned as desired to the tension of the spring. After adjusting the spring to the desired tension, screw 11 is screwed back upwards, so that it first connects part 9 to .part 10 and then leaves the cavity, so that coupled members 9, 10 are rotatable again.

The screw 11 is screwed down until it encounters said recess provided in the bottom of the housing whereby the lever 10 is secured against rotation, but the winder is disengaged and may be rotated relative to the lever 10. The winding means 9 is rotated until another hole lies immediately above the screw 11, and the lever and spring can be reengaged with each other.

The movement of the keeper mechanism is paralleled by that of the damper mechanism. The first 30 of closing movement, or from 110 to 80, are traversed at high speed, followed by a gentle adjustably retarded movement. The high speed is intended to avoid leaving the door open too long in retarded return movement, but is so proportioned as not to interfere with traffic.

The damper system is actuated from the pivot 4. A cam 17 fixedly connected to the pivot 4 presses, as the door closes, against a roller 19 mounted in guide member 18, moving the latter around pivot 4. Guide member 18 is articulated to lever 20, connected to pin 21. In known manner, pin 21 is provided below with a crank and pin moving the damper piston 23 back and forth in the damper cylinder 24, by means of pi;ton rod 22.

When the door is opened, the guide member 18 moves in the direction of arrow b (Fig. 3).

The hydraulic fluid contained in the crank chamber flows through an open ball valve, not shown, in piston 23, into the cylinder chamber. When the door closes, piston 23 moves in the direction of arrow c (Fig. 8), and, under the load of the keeper spring, exerts pressure on From 40 to 110 the the hydraulic fiuid, whereby the ball valve is closed and the fluid must make its way through a passage equipped with regulating valve 25 to return to the space behind the damper piston 23. Depending on the port area, variable by means of valve 25, the closing speed of the door can be regulated. The stroke of piston 23 per degree of door angle is nearly equal from to 0, so that there is an equalized damping effect throughout this range. By means of another valve 26, the final swing (sudden closure over the last 8-10 of closing movement) can be hydraulically controlled, an important point for striking doors requiring to be pushed into locked position. Slot 104 in piston 23, as it overlies the port 26, speeds up the closing of the door so that it will lock. The final slam can be shut olf entirely by means of valve 26, or so adjusted that the final speed will meet specific requirements. The crank 21, in this arrangement of guide member 18, moves in one direction only regardless of the direction of opening of the door.

This achieves a reliable damping action down to final closure, even in the case of swinging doors. Beneath cam 17, a follower 27, Fig. 4a, is provided, resting against the lug 28 of guide member 18 and serving to return guide member 18 when the door is opened.

As may be seen in Figs. 7 and 8, a bore 101 from the oil chamber containing piston rod 22 extends parallel to the longitudinal direction of cylinder. The end of this bore 101 is connected with the working chamber of cylinder 24 by a cross bore 102.

A symmetrically formed cam 27 is located on shaft 4. The shaft, furthermore, extends through an oblong hole of the movable member 18, as seen in Fig. 4a of the drawings. Besides cam 27 of the shaft 4 reacts in any turning direction with either a bearing surface 28 or 28' respectively of member 18, while cam 17, because of its shape, passes a roller 19 located on member 18. At the swinging of the door, member 18 (Fig. 4a), has been shifted upwards. It thereby takes along, piston 25 of the clamping device. At the closing of the door, cam 27, moves member 18 back again, from which results an opposite motion of the piston of the damping device. Because of bearing surfaces 28 and 28', respectively, and the bearing roll of member 18 on one hand, and cams 27 and 17 of shaft 4, on the other hand, the longitudinal position of member 18, depending on the rotating position of shaft 4 is assured.

The housing 1 is so accommodated in a protective casing that it can be set in a horizontal plane about pivot 4 in order to correct inaccuracies of installation.

What I claim is:

1. A hydraulic door-keeper of the type provided with a pivot, comprising a spiral spring, a hou ing to which one end of the spring is attached, a winder to which the other end of said spring is attached, said winder being adjustable to vary the tension of said spring, a linkage comprising tension members connecting said winder to said pivot for returning to closed position a door movably supported on the pivot, cranks rotatably mounted on said pivot and connected to one end of said tension members, a lever secured on said winder and connected to the other end of said tension members, a hydraulic damper cylinder, and a piston in said damper cylinder and means by which said pivot is coupled to the piston, to retard the movement of the door to clofed position, said tension members being pivoted to said lever on one side of a plane passing through said pivot and spring.

2. The hydraulic door-keeper according to claim 1, said means including a cam fitted on said pivot, said cam actuating said piston in the damping cylinder in the same direction. regardless of the direction of the opening of the door, said cam being provided with a follower; a pair of connecting rods in the housing, a crank joining said pair of connecting rods, one of said rods being connected to the piston in the damping cylinder, while the other rod carries the follower of the cam, passages and valves are provided for adjusting the areas so that the damping cylinder piston is drawn back when of the exit passages. the door is opened to either right or left.

3. The hydraulic door-keeper according to claim 1, References Cited in the file of this patent wherein the cranks are loosely mounted on the pivot and 6 the pivot is provided with a catch to drive the cranks UNITED STATES PATENTS alternately in opposite directions during opening of the 799,342 Jordan Sept. 12, 1905 door in opposite directions. 1,064,255 Rixson June 10, 1913 4. The hydraulic door-keeper according to claim 2, 2,669,745 Rydberg Feb. 23, 1954 wherein the damping cylinder is provided with two exit 10 

